Field of the Invention
This invention relates to methods of treating vascular diseases and disorders in diabetic and pre-diabetic patients.
Description of the State of the Art
Until the mid-1980s, the accepted treatment for coronary atherosclerosis, i.e., narrowing of the coronary artery(ies) was coronary by-pass surgery. While being quite effective and having evolved to a relatively high degree of safety for such an invasive procedure, by-pass surgery still involves potentially serious complications and in the best of cases an extended recovery period.
With the advent of percutaneous transluminal coronary angioplasty (PTCA) in 1977, the scene changed dramatically. Using catheter techniques originally developed for heart exploration, inflatable balloons were employed to re-open occluded regions in arteries. The re-opening of the artery by an inflatable balloon is also referred to as “dilatation” of the artery. The procedure was relatively non-invasive, took a very short time compared to by-pass surgery, and the recovery time was minimal. However, PTCA brought with it other problems such as vasospasm and elastic recoil of the stretched arterial wall which could undo much of what was accomplished and, in addition, created a new problem, restenosis, the re-clogging of the treated artery due to neointimal hyperplasia.
The next improvement, advanced in the mid-1980s, was the use of a stent to maintain the luminal diameter after PTCA. This for all intents and purposes put an end to vasospasm and elastic recoil but did not entirely resolve the issue of restenosis. That is, prior to the introduction of stents, restenosis occurred in from about 30 to 50% of patients undergoing PTCA. Stenting reduced this to about 15 to 20%, a substantial improvement but still more restenosis than desirable. For diabetic patients, however, the incidence of restenosis as well as major cardiac events are significantly higher than non-diabetics patients with stenting.
In 2003, drug-eluting stents or DESs were introduced. The drugs employed with the DES are cytostatic compounds, that is, compounds that curtail the proliferation of cells that resulted in restenosis. The occurrence of restenosis has been reduced to about 5 to 7%, a very improved figure. However, based upon the studies to date, the rate of restenosis with DES is still higher for diabetic patients than non-diabetic patients. Thus, there is a need for improved methods for treating vascular diseases and disorders in diabetic and pre-diabetic patients.